In a random sample of 9 residents of the state of Montana, the mean waste recycled per person per day was 2.8 pounds with a standard deviation of 0.68 pounds. Determine the 90% confidence interval for the mean waste recycled per person per day for the population of Montana. Assume the population is approximately normal.
Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.